Those of us who are pickle lovers know that part of the enjoyment of eating a pickle is the crispiness when we take a bite. It's disappointing if that's missing. If your pickles turn out soft there is not much you can do with that batch. But, you can consider what may have happened to prevent it in the future. The following are possible reasons for soft pickles and what you can do about it:
1. Vinegar too weak - use vinegar of at least 5% acidity
2. Insufficient amount of brine - keep cucumbers immersed in brine
3. Pickles not processed properly (to destroy microorganisms) - process pickles in canner after filling jars
4. Moldy garlic or spices - always use fresh spices
5. Blossom ends not removed from cucumbers - slice at least 1/16th inch off blossom end of cucumbers and discard. There is an enzyme in the blossom end of the cucumber that will soften pickles if it is not removed.
Some older recipes call for using pickling lime or alum to make pickles crispy. However, if quality ingredients and up-to-date methods are used they are not necessary.
Visit the National Center for Home Food Preservation for recipes and up-to-date methods for making pickles at home. http://www.uga.edu/nchfp/how/can6b_pickle.html